The present invention relates generally to an improved trailer hitch of the type which couples a towing vehicle and trailer. More specifically, the invention relates to a hitch suitable for accommodating both ball and socket-type couplings and ring and pintle-type couplings.
An improved trailer hitch according to this invention includes a latching arm that has a pair of legs with apertures for mating with and surrounding a guide passage extending completely through the integral body of the hitch. A tubular pin can be inserted through the apertures and the guide passage to fix the latching arm to the body of the hitch.
In one embodiment of the invention, the guide passage includes an insert. The shape of this insert enables the latching arm to attain multiple fixed positions with its head properly located over different sized ball studs. When the pin is inserted through the apertures and the insert of the guide passage, a detent engages the pin and fixes the latching arm in one of the multiple fixed positions--the position appropriate for the ball stud then in use.
The body of the hitch contains a notch that, when the pin is inserted, locks the latching arm in place with its head over the ball stud. This design prevents the latching arm from pivoting or rotating. The latching arm has only three positions: the latching arm is disconnected and independent from the hitch body when the pin is removed, the latching arm can be fixed in an upright position between the rear mount and the transverse column with the pin inserted, or the latching arm can be fixed in its operative position, seated on the notch of the hitch body, with the pin inserted.
According to this invention, the tubular pin has a beveled tip at one extremity to facilitate handling. Near this extremity, the pin is curved to prevent movement of the pin through the apertures and guide passage. The pin has a groove closer to its opposite extremity; this groove engages a lock which prevents theft and inadvertent disengagement of the latching arm from the hitch body. Finally, the pin end opposite the beveled tip is chamfered to facilitate insertion of the pin into the apertures and guide passage.
The integral body of the hitch has a ball housing that accepts a bolt for attaching a ball stud to the hitch body. This design accommodates a variety of different sized ball studs. Therefore, a variety of trailers can be connected to the same towing vehicle without removing the hitch body from the towing vehicle.
The ball stud itself is rounded and has a flat top to accept a ball and socket type coupling. The ball stud also has an integral neck and flange for attaching a ring; the neck and flange perform the same function as a conventional pintle. Therefore, the improved trailer hitch according to this invention accommodates either a socket or a ring of a trailer.
The invention has a wide range and variety of applications and uses. It is particularly useful in truck installations. The integral body of the hitch is mounted on the rear of a truck. The socket or ring of a trailer is inserted over or around, respectively, the appropriately sized ball stud, which is bolted to the hitch body.
Presently known devices that connect trucks to trailers abound. Many of the devices are hitch assemblies that accommodate only the standard ball and socket-type couplings; other assemblies accommodate only the ring and pintle-type couplings. A few known devices can accommodate both types of couplings.
All of these devices, however, may be grouped into two categories. The first category includes more complicated devices, which often require time, a number of steps, skill, and perhaps tools to connect and disconnect the trailer and towing vehicle. Even if assembly is unaffected, the difficulty and expense of manufacturing these devices is often a drawback.
These more complicated devices usually have a latching arm pivotally mounted on the body of the hitch. Because the arm is mounted and not removable, it is subject to forceful impact and damage by the trailer ring or socket on assembly. Moreover, the driver of the towing vehicle may drive away with the latching arm in an inoperative position. A spring mechanism coerces the latching arm into position over the ball stud so that the trailer ring or socket is locked within the hitch. The coercive force exerted by the spring poses a danger for the operator; the spring may cause the latching arm to slam on a hand or finger. The spring also may be lost or become ineffective, thereby impairing the safety of the hitch. In addition, internal springs are relatively inaccessible and cannot be replaced without using special tools and removing the hitch from the vehicle.
The second category of known devices for coupling towing vehicles and trailers includes the more simple structures. These devices usually have an integral ball stud or hook end for attaching the ring or socket of the trailer. This integral design prevents the interchangeability required for the same hitch to accommodate a variety of trailers with different sized rings or sockets. A cotter pin ensures against inadvertent disengagement in these more simple devices. Such a pin, subject to road vibration and shearing forces, may fail and cause accidents during road use.
Simple or complex, none of the presently known devices includes a means to lock the trailer ring or socket within the hitch assembly. Absent such a lock, inadvertent disengagement remains a constant problem and intentional theft remains a concern. Thus, although they are often satisfactory in operation, none of the presently known devices avoids all of the disadvantages common to coupling trailers to towing vehicles.